Carbon articles

Claim 2

IN A PROCESS OF MAKING A CARBON ARTICLE WHEREIN A BLEND OF CARBON PARTICLES AND A POLYMERIZABLE AND CARBONIZABLE RESIN BINDER IS SHAPED AND THE SHAPED MATERIAL IS HEATED IN A NONOXIDIZING ATMOSPHERE TO CARBONIZE SAID RESIN, THE IMPROVEMENT OF PRODUCING A PRECISELY SHAPED CARBON ARTICLE WHEREIN THE PROCESS COMPRISES THE FOLLOWING SEQUENTAL STEPS: A. MIXING A CARBON POWDER HAVING A PARTICLE SIZE OF LESS THAN 200 MESH BSS WITH POLYMERIZABLE AND CARBONIZABLE RESIN BINDER AND AN EVAPORATOR SOLVENT FOR THE RESIN AND CONTINUING MIXING UNTIL THE SOLVENT HAS ESSENTIALLY EVAPORATED TO OBTAIN A FINE POWDER MIXTURE COMPRISING CARBON AND NOT MORE THAN 14 PERCENT BY WEIGHT OF SAID BINDER, B. CHARGING A MOLD WITH SAID POWDER MIXTURE, C. APPLYING PRESSURE OF AT LEAST 800 POUNDS PER SQUARE INCH TO THE CHARGE AND HEATING THE CHARGE IN THE MOLD TO CURE THE RESIN AND BOND THE CARBON WITH CURED RESIN WHILE THE CHARGE IS HELD UNDER PRESSURE OF AT LEAST 800 PSI TO FORM A SHAPED CHARGE, D. REMOVING THE SHAPED CHARGE FROM THE MOLD, E. HEATING THE REMOVED SHAPED CHARGE IN A NON-OXIDIZING ATMOSPHERE AT A TEMPERATURE WITHIN THE RANGE OF FROM 700*C- 1,100*C TO CARBONIZE THE RESIN BINDER, AND F. HEATING THE CARBONIZED SHAPED CHARGE IN AN ATMOSPHERE CONTAINING HYDROGEN TO DEPOSIT CARBON PYROLYTICALLY INTO PORES OF THE CARBONIZED SHAPED CHARGE, TO PRODUCE A HIGH STRENGTH, PRECISELY DIMENSIONED, CARBON ARTICLE WHICH, ON PRODUCTION, HAS UNDERGONE A MOST ONLY SLIGHT DIMENSIONAL CHARGE AFTER BEING FORMED AS A SHAPED CHARGE.

Claim 3

A process according to claim 1 wherein said pressure is about 1,000 pounds per square inch.

Claim 4

A process according to claim 1 wherein said pressure is from 800 to 2,000 pounds per square inch.

Claim 5

A process according to claim 1 wherein said pressure is from 800 to 1,500 pounds per square inch.

Claim 6

A process according to claim 1 wherein said pressure is from 800 to 1,400 pounds per square inch.

Claim 7

A process according to claim 1 wherein said carbon is crystalline.

Claim 8

A process according to claim 4 wherein said crystalline carbon is graphite.

Claim 9

A process according to claim 7 and comprising a further step of processing the high strength carbon article by heating it in an inert atmosphere to above the carbonizing temperature to reduce the hydrogen content in the carbon article.

Claim 10

A process according to claim 8 and comprising a further step of heating the article in an inert atmosphere at a temperature sufficient to graphitize the pyrolytically deposited carbon.

Claim 11

A process according to claim 9 wherein said graphitizing temperature is at least 2,500*C.

Claim 12

A process according to claim 1 wherein said resin binder comprises a phenolic resin.

Claim 13

A process according to claim 11 wherein said phenolic resin binder comprises a phenol-formaldehyde resin.

Claim 14

A process according to claim 1 wherein said evaporative solvent comprises methylated spirits.

Claim 15

A process according to claim 1 in which non-carbonaceous refractory material of particle size less than 200 mesh BSS is included with the initial mixture of carbon powder and resin.

Claim 16

A process according to claim 1 wherein said mold is a metal mold, and wherein the article produced is a precision shaped article having substantially the same size and shape as that of the shaped charge removed from the mold.

Claim 17

A process of making a precision shaped carbon article comprising the steps of: a. mixing a carbon powder having a particle size less than 200 mesh BSS with not more than 14 percent by weight of a polymerizable and carbonizable resinous binder and an evaporative solvent and continuing mixing until the carrier has essentially evaporated, to obtain a first powder mixture; b. mixing a non-carbonaceous refractory powder having a particle size less than 200 mesh BSS with not more than 14 percent by weight of a polymerizable and carbonizable resinous binder and an evaporative solvent for the resin and continuing mixing until the solvent has essentially evaporated to obtain a second powder mixture; c. mixing the first and second powder mixtures together to form a compound powder mixture; d. charging a metal mold with said compound powder mixture; e. applying pressure of at least 800 pounds per square inch to the charge and heating the charge to substantially cure the resin and bond the charge while held under a pressure of at least 800 psi to form a shaped charge; f. removing the shaped charge from the mold; g. heating the removed charge in a non-oxidizing atmosphere at a temperature within the range of from 700*C - 1,00*C to carbonize the resinous bond, and h. heating the carbonized shaped charge in an atmosphere containing hydrocarbon to deposit carbon pyrolytically into the pores of the carbonized shaped charge, to produce a high strength, precisely dimensioned, carbon article which, in production, has undergone at most only slight dimensional change after being formed as a shaped charge.

Claim 18

A process of making a precision shaped carbon article comprising the steps of: a. mixing a carbon powder having a particle size less than 200 mesh BSS with not more than 14 percent by weight of a polymerizable and carbonizable resinous binder and an evaporative solvent and continuing mixing until the carrier has essentially evaporated, to obtain a first powder mixture; b. mixing a non-carbonaceous refractory powder having a particle size less than 200 mesh BSS with not more than 14 percent by weight of a polymerizable and carbonizable resinous binder and an evaporative solvent for the resin and continuing mixing until the solvent has essentially evaporated to obtain a second powder mixture; c. mixing the first and second powder mixtures together to form a compound powder mixture; d. charging a metal mold with said compound powder mixture; e. applying pressure of at least 800 pounds per square inch to the charge and heating the charge to substantially cure the resin and bond the charge while held under a pressure of at least 800 psi to form a shaped charge; f. removing the shaped charge from the mold; g. heating the removed charge in a non-oxidizing atmosphere at a temperature within the range of from 700*C - 1,00*C to carbonize the resinous bond, and h. heating the carbonized shaped charge in an atmosphere containing hydrocarbon to deposit carbon pyrolytically into the pores of the carbonized shaped charge, to produce a high strength, precisely dimensioned, carbon article which, in production, has undergone at most only slight dimensional change after being formed as a shaped charge.

Claim 19

A process according to claim 16 and including the further step of heating the precision shaped article in an inert atmosphere to above the carbonizing temperature to reduce the hydrogen content in the carbon article.

Claim 20

A process according to claim 17 and comprising a furTher step of heating the article in an inert atmosphere at a temperature sufficient to graphitize the pyrolytically deposited carbon.

Claim 21

A method according to claim 16 wherein said carbon is crystalline.

Claim 22

A method according to claim 19 wherein said crystalline carbon is graphite.